1. Field of the Invention
This invention refers to improved apparatus for the fractional distillation and rectification of fluid materials and includes a plurality of components, and more specifically to apparatus units for such purposes and to a modular apparatus comprising a plurality of such units.
2. The Prior Art
The importance and wide uses of distillation and rectification apparatus are well known in the art. A great many types of distillation columns or towers have been designed and described. A typical such apparatus is constituted by an elongated vertical shell defining a processing space in which liquids and vapours flow and contact one another. The mixture to be processed is fed at a suitable point of the apparatus and is heated, generally at the bottom. Evaporation takes place, the vapours rise and are condensed generally at the top of the apparatus. Part of the liquid or all the liquid flows downwards, constituting the reflux. Vapours and reflux contact each other and exchange heat and matter.
The efficiency of a distillation apparatus, which can be expressed in terms of yield and resolution power--both very well known concepts--depends on a number of factors, and of particular importance among them are: (a) an intimate contact between vapours and reflux; (b) a good exploitation of the available space; (c) a good heat insulation. These factors affect on the one hand the good resolution of the original mixture into the components which it is desired to separate, and on the other the amount of material which can be processed in a given space and with a given expenditure of heat. It is obvious that while the desired separation is a datum and must be obtained, it may become too costly if the apparatus is too large and complicated and/or if too much heat is required. Usually there is a certain contrast between process requirements and economical requirements and a compromise of some sort is accepted.
It is a purpose of this invention to provide a distillation and rectification apparatus which is optimal from the viewpoint of all the aforesaid requirements, and in particular achieves excellent resolution and high yields, yet is compact and not cumbersome, is of a simple and economical construction, and has minimal heat expenditures.
It is a further object of the invention to provide an apparatus of modular construction, viz. made up of standard units which may be easily associated and combined in a variety of ways to accomodate and satisfy a wide range of specific process requirements, while being always economical to build and to operate.
These and other objects, which will become apparent as the description proceeds, are attained by the apparatus unit and by the modular apparatus according to the invention.